In comparing real-world outcomes associated with standard-of-care therapies and outcomes achieved with daratumumab monotherapy in clinical trials, daratumumab was found to extend overall survival (OS) in patients with heavily pretreated and highly refractory multiple myeloma (MM).

Kumar and colleagues performed adjusted comparisons of the effectiveness of daratumumab monotherapy versus real-world standard-of-care therapies. To perform this comparison, they used data for patients treated with daratumumab monotherapy from 2 clinical trials: MMY2002 (n = 106) and GEN501 (n = 42). Patients treated with standard-of-care therapies were derived from the International Myeloma Foundation (IMF) chart review of patients with MM who had ≥3 prior lines of therapy and were double-refractory to a proteasome inhibitor and an immunomodulatory drug (n = 543).

In pooling the data from the 2 daratumumab trials, daratumumab demonstrated a median OS of 20.1 months. By comparison, the IMF cohort had a median OS of only 13.0 months.

Using 2 adjusted comparison methodologies, propensity score matching (PSM) and multivariate Cox regression analyses, they found a significant difference in OS in favor of daratumumab. After PSM, a 54% improvement in OS was found in favor of daratumumab relative to standard of care (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.31-0.63). After adjustment for differences in covariates included in the regression analysis, OS again was found to be significantly superior with daratumumab compared with standard of care (HR, 0.43; 95% CI, 0.32-0.59).

The researchers determined that the findings from the PSM and regression analyses were consistent, and suggest that daratumumab is associated with significant gains in OS compared with standard-of-care therapies in this patient population.